Automatic stop for electrically-driven phonographs



' Sept.- l1, 1928.

' J. BRANDSTETTER AUTOMATIC STOP FOR ELECTRICALLY DRIVEN PHONOGRAPHSV- Filed Nov. 5, 1927 Patented Sept. 11, 1928.

UNITED STATES JOSEF BRANDSTETTER,

PATENT oFFICE.

OF CHICAGO, ILLINOIS.

Application led November My invention relates to a phonograph attachment for use with a motor-driven `phono-v graph of the type in which the relnoducer .is carried by a tone arm which moves over a horizontal turntable while the record is being played, and in its general objects aims to provide simple means for rupturing the currentsupply circuit to the motor and speedily halting the record when the tone arm reaches a certain position. Y

y Furthermore, my invention provid-esa simple, cheap and highly compact mechanism for this purpose which can easily be attached to standard types oi phonographs and which can readily be adjusted by the user according to the size ot' the record. It also provides a construction for this purpose in which the electric switch portion is eliectively concealed and housed, while both the trip arm and the starting leverare conveniently accessible.`

Still further and also more detailed objects will appear Jfrom the following specification and from the accompanying drawings, in

which y K Fig. 1 is a front elevation ot `an automat-ic stop embodying my invention, together with a fragmentary vertical section of the tone arm of the phonograph on which the stop is po sitioned. Y

Fig. 2 is a. plan view of the stop with the trip arm disposed in a vertical position, together with a fragmentary section of the rim ot' the turntable of the phonograph. V

Fig. 3 is a bottom view of the same automatic stop. l

Fig.V 4 is an enlarged and fragmentary front elevation of 'the same automatic. stop, together with a vertical section through the horizontal part of the .phonograph cabinetto which the stopI is fastened.

Fig. l5 is view taken from Fig. e. f

Fig. 6 is a` vertical section taken along the line 5 5 of Fig. 4. y

Fig. 7 .is-an enlarged vertical sectionitalren along the line 7-7 of Fig. 2, with the yparts positioned as they appear during the playing of a record.

Fig. 8-is a section similar vto Fig. 7, but taken after the detent has been released so as to actuate the stop. f

vIn the illustrated embodiment, my automatic stop includes a generally flat Vsheet metal base 1 adapted to be fastened to the top ol' the horizontal cabinet board Qwith the major portion of this base underhanging the the bottom ot 5, 1927. serial No. l231,305.

4usual depending rim 3 ot' the turntable which rotates about a vertical axis. Pivoted intervrmediate its ends to the hase 1, as by a vertical pivot pin 3, is a switch lever l which has one arm extending beyond the base and the rim 33, the free cnd ot which arm desirably is formed to afford a handle 5.

The other arm of the switch levermoves over a slot 6 in the base and carries a` rpin 7 which extends downwardly through this slot into a vert-ial perforation 8 formed inthe cabinet board 2. Secured to the bottom of the base is aninsulator 9 which vhas a vertical notch or recess 10 larger than the slot G and underhanging the latter as shownin Fig. 5.

Mounted onithis insulator at opposite sides of the recess 10 are two wire terminals 11, each of which carries a resilient contact 12. These stationary contacts are spaced from each other and disposed so that they will be simultaneously engaged by as movable Contact member (consisting of a metal sleeve 13 carried by the pin 7 and insulatedrom the latter by au insulating sleeve 14) when the switch lever is swung in onedirection by atensioning springl interposed between this. lever and a riser pin 16 fastened to the base.

vTo hold the switch lever at thi-s end of its travel during the playing of a record (namely, with the movable contact member 13 engaging bothv of the contacts 11, as shown in Fig.V 5) I provide a'detent lever of a. bellcrank form pivoted by a horizontal pin 17 to a riser web 18 on the base 1. Gne armY 19 ot this detent extends substantially horiz-:mtally and has a vertical shoulder 2O normally engaging an edge of the switch lever, as shown in Fig. 7, and a spring 21 continuously urges this lever arm 19 upwardly so as to hold the said'shoulder thus disposed. The other and vertical arm 22 ot the bell-crank detent `lever has anv upwardly directedtrip armzi' Vdisposed in extension of it and secured to it throi'lgh a. friction lioint 2li which will permit the trip arm to be adjusted in position with respect to the vertical arm 22. This trip arm is disposed in the path oi the horizontally swinging tone arm 25 ofthe ph nograph and'is adjusted in position according to the size of the record which is being played, so that the trip arm (and hence thedetent arm) will be moved in a clockwise direction in Fig. 1 when the tone arm reaches the end of the record. y lVhen the detent lever is thus moved against the resistance of the spring Q1, the

shoulder 2O clears the edge of the switch lever l and the spring 15 then rotates the switch arm (in a clockwise direction in Fig. 2) until the switch lever t is engaged by another vertical shoulder 26 on the detent arm 19, as shown in Fig. 8. This vlatter shoulder 2G is so positioned that the switch arm will be stopped afterv the movable contact member 18 has moved away from both of the stationary contacts 12, but before the pin 7 reaches the adjacent end of the slot G, thereby preventing undue strains on this pin and on its connection to the switch arm. Consequently, the circuit to the motor 27, which is shown diagramniatically in Fig. 3, is immediately opened. p

In practice, I preferably mount a brake shoe 28 on the switch arms also and dispose this brake shoe so that it will engage the rim 3 of the turntable of the phonograph when the spring 15 draws the switch arm to its said circuit-opening position, thereby quickly halting both the turntable disk and the motor which is operatively connected to this turntable.

`Thus arranged, 'my automatic stop is highly compact and can easily be attached to standard types of phonographs, since this merely requires the boring of the hole 8 in the cabinet and the fastening of the self-contained stop to the top of this board by screws extending through perforations 30 in the base. When thus attached, the switch is entirely concealed and shielded against contacting with needles 'or other metal objects which might short-circuit or otherwise damage it. Moreover, the lentire stop is quite low in cost of manufacture.

However, I do not wish to be limited to the mounting of both thebrake shoe and the movable Aswitch Contact on the same lever, nor to other details of the construction and arrangement above described, since many changes might be made without departing'either from the spirit of my invention or from the appended claims.

I claim 'as my invention:

1. An attachment for a phonograph driven by an electric motor and including al tone aiin automatic stop including' a switch, a pivoted lever controlling the switch and having the movable contact member ofthe switch mounted on the lever, spring means continuously ltending to move the lever in a switch-opening direction, and apivoted detent member hav-r ing an arm disposed in the path of the tone arm' and having'a detent portion normally engaging the said lever to hold the latter in its switch-closing position, the said detent portion beingmoved out of its said leverholding position when the tone arm engages the impact portion.

A phonograph stop Aas per claim 1,'in which thedete'nt member also has another portion disposed foi-'engaging the said pivmally holding the switch in its circuiteopening position, and an extension arm pivoted to the detent lever through' a. friction Joint, and

extending across the path of movement of the tone arm of the phonograph.

4. A phonograph stop as per claim 3, in which the base plate is horizontal, in which the detent lever and the major portion of the switch lever are disposed above the base plate,

and .in which the switch lever has a portion extending downward through the base plate; the switch having its movable contact meinb-er mounted on the said lever portion below the base plate, and the switch alsoincluding a. stationary Contact disposed below' the base plate and engaged by the said member when the switch lever is in its circuit-closing' position.

5. An automa-tic stop for a phonograph driven by an electric motor, comprising a pair of spaced and relatively insulated stationary contacts disposed in the motor circuit, a pivotally mounted switch lever, a movable contact member mounted on one. arm of the switch lever, a bell-crank detent lever pivotally mounted on an aXis transverse of the rairis of the switch lever and having a shoulder on one arm normally engaging the other arm of the switch lever to yhold the latter in a yposition in which the movable contact is out of engagement with the stationarycontacts; a trip aim mounted on the other arm of the detent lever and lextending across the patho'f the tone arm of the phonograph, whereby the movement of the tone arm during the playing of a record will move the detent lever out `of its said switch lever holding disposition; and a spring disposed for moving the switch lever when thus released from the detent, so as to cause the switch lever to move the movable contact into engagement with thestation-ary contacts. 6. For use with a phonograph having a record-holder driven by an electric ino-toi'` and a tone arm movable above the record-holder, an automatic stop comprising: a base, a-bral'- ing member pivoted upon the base and having a friction portion adapted to engage fthe i'ecord holder; a switch including a stationary contact mounted on the basev and a removable contact carried by the brazking'member, the said contacts 'forming portionsof a circuit to the motor, spring means continuously tending to move the braking member to fcause Cil the said friction portion to engage the record and tio-*move the said movable contact into engagement with the stationary contact; and a latching member movably mounted on the base and normally preventing movement of the braking member in the aforesaid direction; the latch member having a portion disposed in the path of the tone arm, whereb-y engagement of the tone arm with the latching member releases the braking member so as to premit the spring means to move the braking member in the said direction.

7 An attachment for a motor-driven phonograph of the type having a horizontally swin 'infr tone arm com rising: a horizontal base provided With a slot, a switch lever pivoted to the base on a vertical axis and having on one arm of the lever an extension Aprojecting downwardly throughthesaidslot,insulat ing means secured to the base below the latter,

a pair of spaced contacts mounted on the insulating means at opposite sides of the slot and both in the circuit to the motor, a movable Contact member carried bythe said extension and adapted to engage both of the said spaced contacts when the switch lever is in one position, a detent movably mounted on the base and disposed for latchingthe switch lever in its said position,a tripV arm associated with the detent and engageable by the tone arm of the phonograph to move the detent out of its said latching disposition; and spring means for moving the switch lever out of its Said position when the detent is released, so as to move the movable Contact member out of engagement with the said spaced contacts.

Signed at Chicago, Illinois, October 31st, 1927.

JOSEF BRANDSTETTER. 

